The present invention relates to an electronic device comprising a first part and a second part which have different functions.
The invention also relates to a circuit arrangement provided with a board and with a first electronic device and a second electronic device having different functions, said first and second electronic devices being mounted on said board.
In recent years, since the demand for mobile communication equipments such as mobile telephones has grown, their size needs to be smaller. In order to meet this requirement, there is a tendency of introducing electronic devices that are able to fulfill multiple functions. An example of this is an electronic device wherein the functions of an antenna and an RF (Radio Frequency) circuit are provided. This kind of device will also be referred to as xe2x80x9can antenna-function-provided electronic devicexe2x80x9d hereinafter. This kind of device is provided with an antenna function, but the characteristic of the antenna may be easily influenced by environmental conditions. For example after changing the circuit configuration of the board on which it is mounted, the antenna characteristic will change as well. Thus, for each circuit configuration of the board a change in the design of the antenna-function-provided electronic device is necessary.
Accordingly there exists a problem that one kind of antenna-function-provided electronic device cannot cope with changes of the circuit configuration of the board. By the way, the board may be any board of insulating material, such as an alumina substrate, a printed circuit board (PCB), an multilayer ceramic board, a glass plate. It may further be a semi-insulating substrate such as a silicon wafer.
In view of the aforementioned problem, it is a first object of the invention to provide such electronic device that can easily cope with environmental changes such the change of the circuit configuration of the board.
It is a second object of the invention to provide circuit arrangements in which the device of the invention can be applied.
In order to achieve this object, the invention provides an electronic device adapted to be mounted on a board and comprising a first part and a second part which have different functions but are integrally formed, wherein said first part and said second part are arranged so as to be separable.
As aforementioned, when the circuit configuration of the board on which an antenna-function-provided electronic device is mounted, is changed, this results in a change of the antenna characteristic of the antenna-function provided electronic device. Therefore, the electronic device in accordance with the invention is adapted such that the first and the second parts are separable. In the case that the device of the invention does not display its desired characteristic, it may be separated into its first and its second part. The first and second parts can then display its respective desired characteristics, and both parts can be connected via a path. This path preferably includes a matching circuit. Thus, in accordance with the invention, even if the circuit configuration of the board is changed, it is not required to change the design of the electronic device of the invention. Instead the change can be coped with by means of separating the electronic device into the first part and the second part.
In an embodiment the electronic device is provided with a substrate that is separable along a boundary portion into a substrate of the first part and a substrate of the second part, and which substrate comprisesxe2x80x94before separationxe2x80x94a through-hole at the boundary portion between said first and said second part, an electrode being present on an interior wall of said through-hole. It is an advantage of the device of this embodiment that an electrical connection between the separated first and second parts can be established easily through the electrode that is present on the interior wall of the through-hole.
In another embodiment the electronic device is provided with a substrate that is separable into a substrate of the first part and a substrate of the second part, which substrate is provided with:
a conductor being present across said first and said second part;
a first outer electrode provided in said first part;
a first connection electrode for connecting said conductor to said first outer electrode, said first connection electrode being present in said first part;
a second outer electrode provided in said second part; and
a second connection electrode for connecting said conductor to said second outer electrode, said second connection electrode being present in said second part.
It is an advantage of the device of this embodiment that an electrical connection between the separated first and second parts can be established easily through the first and second outer electrodes.
In a further embodiment the substrate comprises a scribe line for separating said first part from said second part, said scribe line being formed at the boundary portion between said first part and said second part.
Preferably, the first part has the function of an antenna, and the second part has the function of signal processing. An RF Power Amplifier module is currently manufactured on a ceramic substrate, and it is foreseen that antennas will be manufactured on ceramic substrates. As the antenna is a very sensitive component, the invention is very suitable for reducing design costs for changing the design, as well as for reducing the manufacturing costs of antenna plus RF Power Amplifier Module. Although the use of a ceramic substrate is preferred, the invention can be embodied with any other substrate as well, such as a polymer substrate, a polymer multilayer substrate or any other multi-level substrate. The invention is especially suitable for a device for high frequencies, such as a device that may be used in accordance with the Bluetooth(trademark)-standard. With it the device can be miniaturized to a size of less than 120 mm2.
The second object of the invention is realized in a circuit arrangement of the type mentioned in the opening paragraph, wherein:
said first electronic device comprises a first notch part formed by cutting away a part of said first electronic device and a first outer electrode formed on said first notch part,
said second electronic device comprises a second notch part formed by cutting away a part of said second electronic device and a second outer electrode formed on said second notch part, and
a path is present on said board, said path being for electrically connecting said first and second electronic devices via said first and second outer electrodes. It is further realized in a circuit arrangement of the type mentioned in the opening paragraph, wherein:
said first electronic device comprises a first conductor, a first outer electrode, and a first connecting electrode for connecting said first conductor and said first outer electrode, a part of said first conductor being exposed on a surface of said first electronic device,
said second electronic device comprises a second conductor, a second outer electrode, and a second connecting electrode for connecting said second conductor and said second outer electrode, a part of said second conductor being exposed on a surface of said second electronic device, and
a path is present on said board, said path being for electrically connecting said first and second electronic devices via said first and second outer electrodes. This second circuit arrangement preferably uses a multilayer substrate wherein the first and second conductor are embodied. Also further components may be embodied in this multilayer substrate.
In a further embodiment of this second circuit arrangement that surfaces of said electronic devices, on which parts of said conductors are exposed, are covered with a coating material. This embodiment has the advantage that the reliability of the characteristics of the first and second devices. Note that the first and second electronic devices have come into existence at the separation of the electronic device into its first part and its second part.